Review on Relieve Your Child'S Pain With Reusable Penguin-Shaped Ice Packs For Boo-Boos, Joints, And Teething - Hot And Cold Therapy Gel Beads For Effective Pain Relief (4-Count) by Dee Holt

Got these as more or less a gag for my friend who plays heavy contact sports, but I have to say they work very well. The bumps on them help keep them just far enough away that the cold doesn't get to be too much for a good while. These cool very fast in the freezer, and heat up even faster in the microwave. Best part about having four is that you can keep two frozen at all times and have the other ones ready to be heated to be prepared for anything.